I got one of those in response to my very first story. The person asked what I suppose seemed like a reasonable question to him, but there was no way to reply, even if I had been so inclined.The anonymous e-mails that bug me are the ones where they ask questions I'd like to respond to--but give no way of responding.
Although this particular incident seems like it falls under the rubric: "Never attribute to malice that which can be adequately explained by stupidity."